In order to make an apple pie from scratch, you must first create the universe – Carl Sagan

It was Christmas Night and I was sitting in a girl’s apartment. The two of us were on her couch, one of her bare feet was in my hands, and we were talking about – among other things – the things we’d like to know. Languages we’d like to speak fluently, concepts we’d like to understand, disciplines we’d like to master. I listed off Spanish, photography, music – all of which remain on my mental list of ‘someday’.

What I said at the time was that physics is a field I wanted to know more about because everything that happens, large or small, seen or unseen, happens according to the laws of physics; that this invisible force, while it may not always be apparent, governs us nonetheless. It was a statement which was accurate, if hardly poetic.

And then, as conversations do, the conversation moved on to other subjects and different avenues, and the topic of my curiosity about the mechanics of the world was forgotten.

But what I should have said to her then – now that I’ve put some thought into it and found the words I think express it best – is that physics is the language of understanding and answers; it’s the how and the what of the world. It gives us the raw data of life and existence; add human perception to that and you can begin to see that what we all too often take for granted is truly amazing.

What I should have said is this.

You, sitting there, here with me – in chemical terms, you are 65% oxygen, 18% carbon, 10% hydrogen. 3% nitrogen, 1.5% calcium, 1.2% phosphorus. You are sulphur and chlorine and sodium, magnesium and cobalt, zinc and iodine and selenium and fluorine. You’re a woman, so you are, on average, 2.3 grams of iron (as a man, I’m 3.8).

Smaller than this, you are electrons, protons, and neutrons. Even those electrons, protons and neutrons can be further divided down, into leptons and quarks; the smallest building blocks of matter. This is what you are made from, and you are gravity and electromagnetism and the strong and the weak nuclear force; the four fundamental forces that hold the universe together. And this is not always what you were.

13.73 billion years ago (give or take 0.12 billion years), all there was, everywhere, was a single point. There was nothing else. A singularity; of infinitesimal size, of infinite density and infinite heat. It’s hard to wrap the human mind around this concept; we rebel at trying to consider that everything, everywhere, and everywhen was contained in one indivisible space and time.

And then, in an instant… expansion, and the beginning of everything. Before this moment, there was nothing but this moment. After it, the Universe. And although we don’t know, because our skill doesn’t yet match our curiosity, it’s possible that in this, the moment when time started, those four fundamental forces that keep the Earth turning, that throw shadows behind us when we move through the world, that send quiet ripples across the face of lakes and deepen the sky from blue to black, were one.

This is where cosmic evolution began – the Big Bang kick-started everything that has come since then. With a staggering, omnipotent amount of energy like that released, you get particles being created; brought into existence by sheer force. When people talk about the light of creation, they don’t know just how literal they’re being. Photons, the elementary particle of light itself, flooded through the new-born Universe, a greater pyrotechnic show than any human is ever likely to see. Maybe it will end with a whimper, and maybe it will end with a bang, but it started with light.

Understanding this, how the smallest building blocks of existence inter-relate – this is particle physics, high-energy physics.

There are two laws that become important here. The Law of the Conservation of Energy, and the Law of the Conservation of Mass/Matter. In a closed, isolated system, the sum total of energy doesn’t change. The sum total of mass and matter doesn’t change. Basically speaking, nothing gets in or out – nothing can. Energy may change shape, sure – light a candle and its chemical potential becomes heat and light, clap your hands and kinetic energy becomes sound – but the sum total of energy in the Universe isn’t going anywhere, neither up nor down.

The upshot of this is that all of the matter and the energy in the Universe right now – up to and including the 6.7 x 10 to the power of 27 atoms that are you (that’s 6.7 billion billion billion atoms) were present – if in very different forms – right from the very beginning of everything.

A quick word about your brain.

The human brain is, bar nothing, the most complex and complicated object in human experience. Nothing else comes close. You have 86 billion neurons working away – and an estimated one hundred trillion synaptic connections – inside your head. That’s one hundred trillion connections that flicker on and off with electrochemical energy as you live your life from day to day, that make you who you are. While you study, while you work, while you eat, while you drink, while you sleep, while you wash the dishes or watch TV, these connections are flickering on and off, sending or blocking impulses of thought and reaction.

Now listen carefully.

What all of this means is that while your timelines are vastly different, you and the stars you see when you look up at the night sky were born out of the same instant in space and time. The pieces of you have traveled further distances than you will ever be able to imagine to be here, to be now; they have spun through blinding light and impossible darkness, through gravity and magnetism, riding out the shockwave of creation until this moment.

Your heart beats for the same reason that the ocean tides murmur in and out. You breathe for the same reason that the solar wind sweeps through the space between planets. Your dreams shared their infancy with the sky, and your thoughts are sisters to storms and the sea.

Everything that you are, everything that you’ve done, everything that you will ever be – all of this stems from the single instant in which the Universe began, in light. Whatever else may happen, there is no part of you that is untouched by the truth of this.

This is what physics teaches us, and this is something to be remembered.

Thank you to Laura Spitler at Cornell Astronomy, Sheldon Stone at Syracuse High Energy Physics, and Matthew Kirkcaldie at UTAS Neuroscience for making sure I got my facts straight.

This morning, when I climbed into my car and tried to start the engine, nothing happened. Why? Because I didn’t have the keyfob in my pocket.

With this car it’s possible to make odd mistakes with the keyfob because there is no key attached to it…the little egg-shaped fob uses RF signals to talk to the car, and if the keyfob isn’t physically inside the car, the ignition won’t work. Conceivably one could start the car, go back into the house and change pants, and come back outside to the already-running car and drive away. But guess what? After you turn off the ignition, it won’t start again, because you left the keyfob in the other pair of pants.

The keyfob is also smart enough to know when it’s inside the trunk…and if you accidentally leave the thing in your golf bag, the car is smart enough to pop the trunk lid open to notify you of your absent-minded mistake.

The reason I mention this is because I was thinking on the way to work how it would be nice if I could implant the keyfob technology into my body. I could implant a tiny RF transmitter/receiver in my hand, say, and then I would never need the keyfob at all. And as soon as this occurred to me, I imagined the resistance that people might have to the idea.

Because people are quite romantically attached to their bodies and the idea of being human.

We love using the Internet and DVD players and playing XBox, we love all sorts of technology, but not many of us like the idea of being a cyborg. Darth Vader was the ultimate bad guy during my youth, and only when he was unmasked and uttered the line “Let me look on you with my own eyes,” was he finally forgiven for his evil ways. At the end of Terminator 2, Schwarzenegger’s character says “I know now why you cry, but it is something I can never do.” Only by melting himself, and the chip that is his brain, can humanity be saved (at least for the time being).

It seems we get nervous about the ramifications of blending man with machine. “Will I still be myself?” “Will someone be able to track my every move?” “Will I still have my soul?”

What gets lost in questions of this kind is that nature itself is, at its most basic level, a machine. Everything you see, everything you eat and touch, everything you think you destroy or create, it’s all just component materials organized a certain way. Carbon, hydrogen, and oxygen are the three elements that comprise glucose, fat, and ethanol. Three very different substances, same component materials. The only difference is the way the original elements are put together.

In fact, when you get down to the basic building blocks of matter and energy, at the quantum level, there are only a few types of components. And yet, combining these simple particles with a few patterns creates all the phenomena in the universe…including us.

“Wait,” you say. “I may someday return to dust, but at the moment these cells are all mine! Right?” Actually, no. The cells that comprise your body turn themselves over at different rates, but over the course of several years your body becomes completely new cells. (The exception here are neurons in the brain, though even those are altered when atoms within the neurons are recycled.)

How can YOU be YOU if all the material in your body was, a few years ago, contained in plants and animals and air scattered across the Earth?

The answer is: information. Instructions in your DNA tell your body what to do with the fuel you take in. Think about it: You eat a steak (or peanut butter, or some kind of protein) and a little later it becomes muscle fibers in your bicep. Or, you eat a steak, and another steak, and you never exercise, and instead the calories turn into fat. Your body is simply an organic machine, albeit a very, very complex one

So…if someone devised a chip that you could implant in your brain, and it would increase your mind’s processing speed and memory accuracy, would you want one?

What if, using nanotechnology, we could repair cellular damage and clean out arteries, would you want that?

Nanobots are very small machines…which sounds scary until you realize that they are not much different than regular molecules. They just have a few instructions that tell them what to do. Whereas a typical molecule is sort of “dumb,” a nanobot would be a molecule with a purpose. We already genetically engineer bacteria to do things for us (like help us make cheese).

I know it doesn’t seem very romantic to use technology to enhance or alter our bodies. But think about all the ways you intentionally alter your chemical makeup. How many of us use wine to enhance a romantic evening? How many people smoke to calm their nerves? How many of us use pharmaceutical drugs to get over an illness? Or even “natural” medicine? All those things alter your body’s chemistry.

Why would a chip be any different?

Finally, there is the issue of immortality. Would you guess that, in a way, all of us are immortal? Sure, your body eventually dies, but the DNA instructions used to create your body…those will live on if you have children. Bodies age and die primarily because replication errors cause DNA information to be lost. There may be ways in the near future to slow or halt the process that results in these errors.

If you could, would you want to live for two or three hundred years?

Of course, the longer you live the more likely it is that you will be involved in a fatal accident. What if you could use a chip to periodically upload the information in your brain to a computer? A sort of backup process?

When you think about it, the core of who we are is the information stored in our brain. All of our hopes and fears and loves and successes and failures are basically just information encoded in neurons. If you could back that up somewhere for download later, would you do it?

Would you want to “live” in a computer that was connected to the Internet?

How different would your MySpace (or Facebook, etc.) relationships be? All the friends you have online that you never see in person…would that be different? Hopefully no one prefers MySpace to real life, but would a computer existence be preferable to death?

I used to be frightened of death. The idea of “me” ceasing to exist, that the world would go on without me, that I would miss out on great discoveries (such as life on other planets), really bothered me. But in the past few years I’ve wondered if maybe eternal life would be boring.

Obviously we’re romantically attached to our bodies and the idea of being human because that’s how our DNA has programmed us to feel. We reject too much progress because it seems artificial…but what does “artificial” really mean? How do you define such a concept?

There will come a time in the not-so-distant future when we will be able to outsmart DNA. It’s not a matter of if, but when.